The invasive hemlock woolly adelgid (HWA) was recently detected in Ontario and threatens the province’s eastern hemlock forests. A novel risk matrix was created from species distribution model-based predictions of climatic suitability and host abundance data to predict future HWA establishment and impact in Ontario. We found that HWA can infest townships across southwestern Ontario, but the low proportion of eastern hemlock will limit its impact. Under a low emissions climate change scenario, most eastern hemlock in the province will be threatened by mid-century. The combination of host abundance and climatic suitability values from species distribution models was an effective method to model cumulative risk posed by invasive species using readily available datasets. The preparation of such models allowed the presentation of data in a manner interpretable and applicable to forest managers and invasive pest management practitioners.